The invention herein relates to processes for curing insulation on wire.
Various types of electrical wire, including particularly magnet wire, are insulated by coating thereon a layer of curable organic insulating material such as phenolic resin. The insulation is applied to the wire in a wet uncured form and thereafter must be passed through a drying step and a curing step to form the finished insulating coating on the wire.
In the past such drying and curing steps were considered to be distinct operations even though they might be performed in the same piece of equipment. Fuel usages were high because the drying air and the curing air were heated separately. The drying and curing air streams each picked up volatile combustible materials from the coating during the drying and curing operations, but the volatile combustible materials in each stream were separately burned in an external fume burner, with the resulting gases being vented directly to the atmosphere, so that all the sensible heat was lost. In view of this substantial energy loss, it would be desirable to have a process and associated equipment to enable that heat energy to be recovered for use in the wire coating operation.